Games these days seem to be getting more and more complex. Whereas an early first person shooter such as Wolfenstein 3D contained only 4 usable weapons, we now have games such as Borderlands, which claims to offer over 17 million (and its sequel, even more). Strategy games also feature an ever expanding arsenal of units, and games of all types strive to pack in more bells and whistles than ever before. But is all this added complexity a good thing, or does it actually detract from gameplay in some ways? The truth is, it's quality not quantity that matters, and sometimes less is more - which leads me to the topic of multifunctionality in games.

To illustrate what I mean by multifunctionality, lets look at the parakoopas from Super Mario World (above). Initially, a parakoopa is a flying enemy, but once Mario stomps on its head, it loses its wings and becomes a regular walking koopa. If Mario stomps on that, it retreats into its shell, becoming an item that can be picked up and carried, and used as a throwing weapon to kill other enemies (becoming a hazard to Mario if it then bounces back). That's a lot for one enemy to do, when you think that the enemies in most platformers do little more than walk towards the character and perhaps shoot occassionally, and it makes parakoopas so much more interesting.

Mole Mania (above) is another game by the same legendary designer responsible for Super Mario World (and a huge number of other classic Nintendo games), Shigeru Miyamoto - and again, it contains some great examples of multifunctionality. The screenshot above shows a level from the game, with the aim being to push and pull the black ball to the exit at the top of the screen. However, to get the ball over the spikes, the player must throw it, in which case it will continue rolling all the way to the hole, and be sent back to its original position. The solution is to fill that hole by pushing a barrel into it (left), allowing the ball (and other objects) to pass over it. However, once a barrel falls into a hole, it can't be removed and it becomes a permanent barrier to movement underground (center), which is required in virtually every level - the most difficult levels in the entire game are ones which require careful use of barrels. One final use of barrels is as a weapon - they can be thrown at enemies to kill them (right).

Going back to weapons for a moment, let's look at Incubation (above). The game features a total of 12 usable weapons - so not 17 million, but quite a good selection nonetheless. What makes it so interesting is that the weapons are not only very different from one another, but that most of them also have two different "firing modes" which serve significantly different functions. For example, the flamethrower can be used as a regular ranged weapon, or to create a carpet of flame as a temporary barrier to enemy movement; The machinegun can focus its fire on a single target, or can spread it over a group of enemies; The laser can either inflict damage, or can paralyze an enemy; The grenade launcher can fire explosive grenades, or it can launch mines which only detonate when an enemy walks over them; The advanced combat gun has a bayonet, which makes it an effect melée weapon.

In the similar game X-Com, multifunctionality is achieved through different ammunition types - several of the heavier weapons can use either armor-piercing (normal), high explosive (area effect), or incendiary (area effect & fire) shells/rockets. In addition, smoke not only provides cover, but also causes stun damage - so one way of capturing an alien alive (essential to long term progress) is to trap it and use smoke grenades.

The important thing in both games, from a gameplay perspective, is that the different weapons/modes/ammunition can and must be used in different situations, and in different ways, in order for them to be effective. This is what adds the extra element of decision making, and ultimately makes the weapons fun and interesting (Sid Meier, creator of Civilization etc, described a good game as "a series of *interesting* decisions" - http://www.gdcvault.com/play/1015756/Interesting ).

The weapons in Borderlands are procedurally generated, which in this case means that they have been assembled from a randomly selected assortment of component parts - so while there may technically be over 17 million combinations of parts, the inevitable result is that the weapons only vary slightly from one another. The key question is: Do you change the way you play, depending on the weapon you are using? If the answer is "no", then from a gameplay perspective, there is no need for the different weapons to all exist.

The picture above shows the full range of units available in the strategy game Gameboy Wars (top) and its successor Advance Wars (bottom). You can immediately see that the earlier title features almost twice as many different units - and that's before you include the 15 additional "S" units that are available as upgrades. Clearly the developers of Advance Wars *could* have included all those units - so why didn't they?
Part of the answer is that many of the units in the original game were too similar to one another, meaning that they would not be used differently, and that there would be little reason to choose one over another - so in short, they were unneccessary. Also, some units were overpowered or underpowered relative to other units in the game, so either they were redundant or they made another unit redundant. In addition, some other units were too specialized, meaning that they could only used effectively in a very particular situation, and were otherwise useless - making them less fun and interesting to use, because they will only ever be used in the exact same way (for example, the supply plane serves no purpose other than to refuel other planes).

What the developers of Advance Wars wisely did, was to get rid of the "duplicate" units, and then combine the functions of many of the more niche units into just a couple. For example, in the original Gameboy Wars, there were no fewer than three different ground units for transporting infantry (APC, IFV and Convoy) - but in Advance Wars, there is only the APC. In Gameboy Wars, there were separate units for resupplying ground, naval and air units (supply truck, tanker and supply plane) - but in Advance Wars, there is just that APC again, now able resupply units of all types - multifunctionality at its best!
Now, is it realistic for an APC to resupply a high flying fighter jet? No, of course it isn't (unless you envisage some kind of skyhook based system?) - but what it does do, is make the game more playable, by obviating the need for that otherwise useless supply plane. In many cases, multifunctionality will make a game more realistic and immersive.

Even with fewer units than Gameboy Wars, Advance Wars still has balance issues - the mech (bazooka) infantry is overpowered relative to other units, leading to the dominant strategy of "mech spam". However, the more units/items/characters etc a game includes, the more difficult it will be to balance them.

In Golden Sun (above), there are both combat psynergies (magic spells) used in battle, and utility psynergies used to solve puzzles - and in some cases, the same psynergy can be used for both.
For example, the "frost" psynergy can be used to turn puddles of water into columns of ice, which is necessary for solving certain puzzles - but it can also be used as a (relatively weak) attack, blasting the target with ice crystals. Similarly, the "growth" psynergy can turn a small plant into a climbable vine, or attack with thorns.

The game also includes a unique "Djinn" system - Djinn being collectable elemental creatures, with multiple functions. Firstly, they can boost a character's basic stats. Secondly, they each have a unique function of their own, ranging from attacks to stat boosts etc. Thirdly, they influence the psynergies available to a character (they are each aligned to one of four elements, and different combinations of elements open up a different selection of psynergies). Finally, multiple djinni of the same element can be "summoned" together to make some immensely powerful attacks.

Cave Noire (above) is another example of a game where the same magic spell can have multiple functions. In the screenshot above, the "boulder" spell is used to create a boulder to block the skeleton's movement (center), and to create a path to the chest (right). This is good, but it can also be seen as a missed opportunity - although it would seem logical to kill the skeleton by dropping a boulder on its head, the game does not allow this.

This is one case where increased multifunctionality would enhance realism and immersiveness. As another example, it can be frustrating if a player possesses a shotgun, and is forced to resort to fighting with their bare hands when they run out of ammunition for it - adding the ability to use the shotgun as a melée weapon (even a relatively ineffective one), would be more realistic. Likewise, games often feature objects in the background scenery that would be useful, but cannot be interacted with, which kills the player's suspension of disbelief. Many more modern fighting games allow background objects to be used as improvised weapons - Fighting Force was one of the first, and allowed the use of everything from lamp posts to tires (ripped from a car) as weapons.

The reason the developers of Cave Noire didn't allow for the boulder spell to be used in combat, is most likely because it would make the spell overpowered (there's already an attacking fireball spell), but it could even be that it's not something the developers ever envisaged players attempting to do.

Scribblenauts (above) is perhaps the ultimate expression of multifunctionality. It allows the player to create items which interact with the other objects in the scene, in order to achieve a desired outcome. The truly amazing thing is that the player can create virtually *anything*, with the list exceeding 22,800 unique objects, ranging from animals and machines, to famous people and household objects - and unlike the weapons in Borderlands, these are not procedurally generated. Clearly, with that many objects all able to interact with one another, there's no way that their interactions could have been hardcoded by the developers. Instead, each item is assigned a list of properties, which determine how they behave. For example, a tiger might be "aggressive", which means it will attack things; it might be a "mammal", which means that it is also "made of flesh", which in turn means that its meat can be eaten. All of this means that objects have virtually unlimited functionality, and players can use them in ways which the developers never could have envisaged - something called "emergent gameplay".

In future, this could easily be something that is seen a lot more, as more powerful hardware allows game environments to become ever larger and more detailed. It may not be too long before there are open world games which model everything down to the smallest item, and allow them to be used by the player in every way imaginable.

It's interesting how advanced wars had nearly half it's units removed and replaced with multi-functionality. If you think about it, it gives dimension to all the decisions you make. For instance, you may send an APC to drop off troops, but it opens a window to supply fuel to near by recon.